This represents a competitive renewal of an application to study the impact of hospitalists on the care of older hospitalized patients. We have used 5% national Medicare data to describe the growth of hospitalists from 1996 through 2006 to evaluate the association of care by hospitalists with length of stay;to assess how the impact of hospitalists on length of stay varies by patient and hospital characteristics, and disease severity;to examine how hospitalist care effects continuity of care during hospitalization and across the transition from community to hospital and back;to describe the growing role of hospitalists in caring for surgical patients;and to begin to describe the outcomes of hospitalist care. We have found evidence of cost shifting;that is, hospitalist care is associated with reduced hospital length of stay and costs but increased Medicare expenditures post discharge. Our Specific Aims are: 1. Examine the association of care by hospitalists with processes and outcomes of care, focusing on quality indicators at the hospital level. Is adoption of a hospitalist model by a hospital accompanied by improvements in quality? 2. Examine the impact of adoption of an electronic medical record (EMR) system on hospitalist care. Does implementation of a complete EMR impact the relative advantage of hospitalists on length of stay? Does implementation of an EMR in a hospital system reduce or eliminate the association of hospitalist care with increased utilization and costs post discharge? 3. Explore the use of 100% Medicare data to assess performance of individual hospitalists. We will address these aims using the 5% national sample of Medicare charge data from 1995 through 2010, and 100% Medicare data from Texas for 2000-2010. PUBLIC HEALTH RELEVANCE: Over the past 10 years patients hospitalized for medical illnesses are increasingly more likely to be cared for by full-time hospital physicians, termed hospitalists. We propose to study how care by hospitalists affects overall quality of care in a hospital. We also will use 100% Medicare data to describe variation among hospitalists in their performance;for example, in the percent of their patients who are readmitted to the hospital after discharge.